Firstly, you have posted this in the general paintball subreddit. You are likely going to get a lot of disparaging opinions from paintball players here who do not play magfed on the merits (Or relative lack of them) of magfed markers. So I am going to say that yes, when compared to most speedball oriented and hopper fed markers, magfed markers don't hold a candle in terms of performance compared to a speedball marker. We know, we know.

So with that all out of the way, allow me to give a magfed players opinion.

So in magfed (And mainly paintball in general but this particularly applies to magfed) the marker a player chooses to play with is somewhat like a religion. Theirs is the right one and if yours is different then their one is better. So telling people that X marker is better than Y marker is an exercise in futility when a marker becomes an identity, as the T15 has become.

So I will try to be objective initially and leave my opinion till the end.

Magfed paintball has two leading contenders when it comes to markers.

The first is the EMF100 by Planet Eclipse. It is basically a magfed version of their EMEK 100 hopper fed paintball gun. They simply added some Picatinny rails and added a magazine slot and made the hopper feed more discreet and hideable.

The other marker is the T15 made by First Strike. This marker has been designed to copy and ape the performance of an AR-15 rifle as much as possible, to the point it shares about 60% commonality with AR-15 parts and components. So a large amount of furniture made for an AR-15 (Handrails, grips, cocking handles, etc) will work on this marker.

Both markers mechanical in their action, are comparatively priced, can fire first strikes and both markers are very robust. However beyond that, they are very different markers.

The T15 was designed many years ago by a chap called Tyler Tiberius (Cool name) for the milsim crowd. There is no other way of putting it. People who want their markers to look like a real firearm. As such the design philosophy behind it was "Make it look like an AR-15 first and foremost, and then add the paintball components in as a secondary consideration". And to be fair, through some ingenious engineering, it works. But it comes at a cost. T15 markers are perhaps some of the most complex paintball markers on the field today, using a complicated system to feed air and run the bolt. As such, they require a lot of maintenance and understanding of how they work to keep them running smoothly. However the upside to this is that you get a marker that is REALLY customisable, and if you like that kind of thing, the T15 can be a real hobby horse. And I guess if you like looking like you are playing real life COD, there is that too. However as an objective fact, I have never been to a magfed event where there wasn't someone, somewhere, having an issue with a T15 at some point in the day. More to go wrong, more will go wrong as the old saying goes!

Then there is the Planet Eclipse EMf100.

Here the design philosophy was very different. Here it was "Make it a good paintball marker first and foremost, and the design can come after". And by taking the EMEK100 which was an extremely reliable platform and slapping magfed elements onto it, that is what they did. As such it is an extremely simple marker that almost never goes wrong. It is far simpler, and it often gets criticisms levelled at it that it is ugly, but at it's core it is so simple it just works all the time. And people like that reliability a lot. To the point a lot of players now accept it is the most widely used marker in magfed paintball (There are no conclusive surveys that can tell us for sure). Also, the customisation aspect of it is catching up to the T15 to some degree, with a lot of third party manufacturers making components for it now that change its appearance in various ways.

Other aspects of variation between them are there magazines. The T15's magazines are very good and will fit in standard pouches. The EMF100's are a LOT bulkier which some people do not like. However they have a "side gate" mechanism that a lot of people love as it makes loading magazines a breeze. The EMF100 was originally designed to use Dye DAM (Another marker) magazines before Planet Eclipse designed their own, and as a result the Dye Dam and EMF100 can interchange magazines. Which magazine system you prefer comes down to whether you like the slimmer, smaller easier to carry mags of the T15 or the bulky yet super easy to load convenience of the EMF100.

So to stop being objective and give my opinion on the best marker. Hands down the EMF100 unless you like customising your marker. It's just so reliable and an easy life compared to the T15's "Nuances". This is a hotly debated point, but I also believe its a more efficient marker when it comes to air usage as well.

I actually own both. The T15 is a cool toy to customise and for photos and you can certainly play a game of paintball with it just fine most of the time. However that EMF100 comes with me everywhere I go, because I know its going run and run when I need it to. Even when it is not my main marker (Because my main marker is a Dye Dam), it is in my bag as a back up marker.

If this is your first marker, get the EMF100. If not, decide if you are a tinkerer or not, and choose accordingly.